A light source of a projector is generally a system that can generate three primary colors of red, green and blue lights. However, for the luminous efficiency of a solid-state light-emitting element, a blue solid-state light-emitting element generally has the best luminous efficiency. therefore, most of the current light sources are to excite light of various colors by adopting a blue solid-state light-emitting element cooperating with a fluorescent color wheel, instead of a method of directly emitting a red light by a red solid-state light-emitting element or emitting a green light by a green solid-state light-emitting element, thereby improving the luminous efficiency of a light source system. However, in order to improve the saturation of the light source, a corresponding filter is generally used for filtering.
In the color wheel used in the existing light source system, in order to obtain efficient red light, a double color wheel structure is adopted mostly, that is, two driving devices drive a fluorescent wheel and a filter wheel respectively. As a result, the structure is complicated and the cost is high. However, when a single color wheel is used, high-efficiency three primary color output cannot be implemented, and thus we design this solution.